New “Cobot” ISO/TS a Good Next Step

The recently published ISO/TS 15066 offers guidance to ensure the safety of people working alongside collaborative robots, but future refinement is expected.

“Cobot” is slang for “collaborative robot.” Cobots vary in design, but they all feature some combination of technologies that enable them to function safely alongside humans in a shared area, unlike conventional industrial robots that operate autonomously inside a safeguarded cell.

These types of robots are still relatively new, so the existing ISO 10218 standards covering safety requirements for industrial robots published in 2011 don’t adequately address their safe integration. This prompted representatives of the automation community to develop the ISO/TS 15066 technical specification, which was published in February and serves as a supplemental
document to facilitate cobot integration.

One important aspect of ISO/TS 15066 is that it offers guidance for robot integrators and manufacturing personnel to conduct more sophisticated preliminary risk assessments of both the cobot system and the environment it will share with humans. The challenge in creating ISO/TS 15066 was establishing a means to determine what is “safe enough” in terms of cobots and humans interacting together, given the range of applications for which cobots might be used, the different types of grippers/end-effectors and the types of workpieces they might manipulate.

Germany’s University of Mainz was called on to conduct a pain-onset study. Tests were conducted using 100 people to establish force and pressure limits on 29 body areas (mimicking possible contact with a moving cobot). From that, the maximum speed a cobot can move in a collaborative area can be determined so integrators can adjust cobot speed to ensure potential contact doesn’t exceed those thresholds.

However, Esben Østergaard says this is a new area of research, and that additional studies likely could result in revisions of these values. Mr. Østergaard is the chief technology officer for Denmark cobot manufacturer Universal Robots, one of the organizations that helped create the technical specification. He also admits ISO/TS 15066 is a bit complicated to follow, and that refinement of the risk-assessment guidance it provides is welcome and expected.

“We acknowledge that the world needs a conservative approach toward robot safety, but there is still a lot of ongoing research on safe human-robot interactions and how to define practical guidelines in order to unleash the full potential of collaborative robots,” he says. “We look forward to following this work as it evolves.”

In addition, because documents like these invariably lag technology development, they tend to be retrospective. That said, ISO/TS 15066 is a good next step in offering direction for the safe application of this evolving robot technology.